Employee
表包含所有员工,他们的经理也属于员工。每个员工都有一个 Id,此外还有一列对应员工的经理的 Id。
+----+-------+--------+-----------+ | Id | Name | Salary | ManagerId | +----+-------+--------+-----------+ | 1 | Joe | 70000 | 3 | | 2 | Henry | 80000 | 4 | | 3 | Sam | 60000 | NULL | | 4 | Max | 90000 | NULL | +----+-------+--------+-----------+
给定 Employee
表,编写一个 SQL 查询,该查询可以获取收入超过他们经理的员工的姓名。在上面的表格中,Joe 是唯一一个收入超过他的经理的员工。
+----------+ | Employee | +----------+ | Joe | +----------+ 答案: select * FROM employee AS a, employee AS b where a.ManagerId = b.Id and a.Salary > b.Salary拓展:选出有经理的员工即manageredId不为空 select Id from employee where ManagerId is not null :当where中id对应有多个值的时候使用in 查出不为空的经理的薪水 select ManagerId from employee where Id in (select Id from employee where ManagerId is not null)
原文地址:https://www.cnblogs.com/jiyanjiao-702521/p/12625242.html
时间: 2024-10-14 07:09:59